1. Field of the Invention
The present invention relates to a photochromic flesh-colored pigment and a process for producing the same and, more particularly, to the improvement of a pigment using titanium oxide.
2. Description of the Prior Art
A flesh-colored pigment is essential as a cosmetic material, in particular, as a material of foundation. Since the flesh color is representative of a neutral tint tinged with warmth, a flesh-colored pigment is one of the pigments much in demand which is applied to various daily necessities.
It is hitherto difficult to produce a flesh-colored pigment from a single component, and general flesh-colored pigments are composed of an iron oxide pigment with an appropriate amount of red (red oxide Fe.sub.2 O.sub.3), yellow (yellow oxide FeOOH) and black (black oxide Fe.sub.3 O.sub.4) mixed therewith.
However, since the dispersibility is different depending upon the kind of iron oxide and, especially, red oxide and black oxide have poor dispersibilities, the pigment contains many grains. In addition, the pigment has a different color depending upon the mixing time. When the mixing time is long, a reddish color disadvantageously becomes vivid.
As a countermeasure, a skin cosmetic preparation bringing out a flesh color by a single pigment has been developed (see Japanese Patent Laid-Open No. 98009/1984). A flesh-colored pigment obtained by substantially uniformly coating the particle surfaces of titanium dioxide with at least one selected from the group consisting of hematite and amorphous hydrous iron oxide is provided.
Recently, a pigment is required to have various functions. For example, a pigment the tone of which varies with the optical conditions, in other words, a pigment provided with what is called photochromism (or phototropy) has attracted public attention.
As products to which such photochromism is applied, dimmer glass, color-variable make-up cosmetic preparation, etc. have conventionally been developed (see Japanese Patent Laid-Open No. 49312/1981 and 10079/1981), and application of photochromism to a wider field has been expected.
However, no flesh-colored pigment excellent in productivity and usability and provided with photochromism has yet been developed. In view of the wide application range of a flesh-colored pigment, the development of such a flesh-colored pigment has been strongly demanded.